Etan Patz's mother testified for the second time Tuesday at the murder trial of Pedro Hernandez stemming from the 1979 disappearance of the 6-year-old, to rebut defense claims that another longtime suspect in the case may have had access to her son.

Defense witnesses testified that Jose Ramos, a convicted pedophile, told prison informants in 1991 that he knew Etan through a girlfriend who baby-sat the boy and had access to the home, but Julie Patz said it wasn't true.

She said the woman, Susan Harrington, had chaperoned her son to and from school during a bus strike in 1979 and had helped out at an informal day care center at the Patz home, but never baby-sat the Patz children by herself.

Etan vanished on May 25, 1979. Hernandez, 54, of Maple Shade, New Jersey, said in a disputed 2012 confession that he strangled the boy, but the defense says he suffers from a mental disorder and has tried to cast suspicion on Ramos based on incriminating statements he made from 1988 to 1991.

Julie Patz first testified at the start of the trial on Feb. 2, telling jurors what she remembered of the last morning she saw Etan. Although her husband, Stan, and other family members have attended every day, she hasn't been in the courtroom since.

"I chose not to subject myself to the details of the alleged confessions because I would not be able to dismiss it . . . . and would have difficulty sleeping," she explained.

Ramos has admitted molesting Harrington's son, according to testimony. Patz said she recalled hearing about a man named Jose, and knew Harrington had "problems" without being sure of the details on men, drugs and alcohol.

But other than walking Etan and other neighborhood children home during the school bus strike, she testified, Harrington never went missing for any period of time with her son. "Not more than a minute or two," Patz testified.

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Ramos, now 71, has been twice convicted of child molestation in Pennsylvania, and is imprisoned for lying about his whereabouts on a required form for sex offenders. He has said he will invoke his Fifth Amendment rights if called as a witness.

A prosecution psychiatric expert is expected to dispute defense claims about Hernandez's mental state when the trial resumes in Manhattan Supreme Court on Thursday. Justice Maxwell Wiley told jurors that testimony in the 2-month-old trial may end next week.